The proposed research consists of a detailed analysis of the function and anatomical organization of the amygdala of the rhesus monkey (Macaca mulatta). The general hypothesis underlying this research is that motivated behaviors, such as sex, aggression, and hunger, require sensory guidance, and that the amygdala is the locus where the various sensory systems connect with the central autonomic and neuroendocrine systems that are closely associated with these motivated behaviors. I am in the final stage of assessing the contribution of the cortical sensory systems to the nuclei within the amygdala. I now propose to characterize the further projections of these sensory-related amygdaloid nuclei. Using radioactively-labelled amino acids, I intend to determine the anatomical interrelationships of the amygdaloid nuclei, and also their projections to other parts of the brain, in order to see whether connections are formed with the autonomic and neuroendocrine nuclei of the hypothalamus. As a beginning toward understanding the function of the sensory afferents to the amygdala, monkeys with bilateral amygdaloid lesions will be tested on initial learning, and reversal learning, of somatosensory, visual, auditory, and olfactory tasks. These results should indicate which sensory systems influence the amygdala, and something of the nature of the sensory deficit. Finally, to show that the sensory cortex functionally interacts with the amygdala, a combination of unilateral cortical and amygdaloid lesions will be made which anatomically isolates the remaining amygdala from the remaining sensory cortex. If the behavioral results are similar to the bilateral amygdalectomized animals, the total behavioral evidence would suggest that sensory cortex and amygdala functionally interact, and some idea would be obtained regarding the nature of the information transfer that occurs between the two structures.